ISWI Chromatin Remodeling Complexes

Publisher Summary Studies have identified ISWI chromatin remodeling complexes through biochemical purification of chromatin remodeling activities in vitro and by cloning of ISWI homologs based on sequence homology. These studies, combined with major progress in genome sequencing of various model organisms, have also identified a large number of ISWI chromatin remodeling factors. In addition to this, a wide variety of in vivo functions and in vitro biochemical activities of ISWI complexes have been identified. Because ISWI complexes are involved in a diverse array of DNA dependent processes, elucidating the mechanisms of ISWI functions significantly increases the understanding of these essential biological processes. At the organismal level, ISWI complexes are required for normal development of Drosophila, mouse, and C. elegans. The double mutation of two ISWI genes in S. cerevisiae, ISW1, and ISW2 causes a modest temperature sensitive growth phenotype. At the molecular level, the role of ISWI in transcriptional regulation has been extensively studied, but its involvement in DNA replication and in the maintenance of higher order chromatin structure has been uncovered.